Quantum Breakthrough Extends Secure Mobile Communication by 150% Without Constant Calibration
A new quantum communication protocol has been developed to improve security and distance in mobile applications. The reference-frame-independent (RFI) quantum secure direct communication (QSDC) protocol extends transmission ranges by over 150% compared to older single-photon methods. This breakthrough could make quantum-secure messaging more practical in real-world conditions.
The RFI QSDC protocol removes the need for constant, precise calibration, simplifying its use in mobile settings. Unlike previous systems, it only requires calibration in one direction while tolerating misalignment in the other two. This flexibility helps maintain performance even when conditions change.
At a channel loss of 10 dB, the protocol achieves secrecy capacities of 0.189 and 0.192 bits per pulse. Optimising the pulse intensity of signal states further boosts its range, reaching distances of 27.875 km and 26.750 km—an improvement of up to 155.9% over earlier methods. Security testing confirms its resistance to collective attacks and photon-number-splitting (PNS) attacks. A new parameter, C, has also been added to the security framework to strengthen defences against reference frame fluctuations. Future research may focus on testing the protocol in real mobile environments and addressing channel imperfections. These steps could push the technology closer to everyday use.
The RFI QSDC protocol expands secure communication distances significantly while reducing calibration demands. Its resilience to attacks and adaptability to dynamic conditions suggest potential for wider adoption in quantum key distribution. Further experiments will determine its effectiveness in practical, mobile scenarios.
